A tomographic imaging apparatus for the eye portion such as an optical coherence tomography (hereinafter referred to as OCT) is usable to three-dimensionally observe a state inside a retinal layer. In recent years, the tomographic imaging apparatus has attracted attention because it is useful in accurately diagnosing disease.
In an ophthalmologic diagnosis, there can be used a volume image for grasping the state of the entire retinal layer and a high image-quality two-dimensional tomographic image for grasping a layer which is not imaged on a low image-quality tomographic image. The volume image refers to aggregation of the two-dimensional tomographic images.
The image quality of the tomographic image acquired by the OCT depends on the strength of near infrared light incident on a retina. For this reason, the strength of the light with which the retina is irradiated needs to be increased to improve the image quality of the tomographic image. However, from the viewpoint of safety, the strength of the light with which the retina can be irradiated is limited. This requires the high image-quality tomographic image to be generated while the retina is being irradiated with near infrared light within the unquestionable strength of the light from the viewpoint of safety. To meet such a requirement, Japanese Patent Application Laid-Open No. 2008-237238 discusses a technique in which two-dimensional captured tomographic images are superposed on each other to generate a noiseless sectional image.
In Japanese Patent Application Laid-Open No. 2008-237238, however, a plurality of tomographic images are merely subjected to arithmetic mean. For this reason, in a case where correlation is low between the added tomographic images, a reduction in diagnosis information can be increased. In particular, since involuntary eye movement occurs in eyes, the entire areas of adjacent images are not always similar.